Process and apparatus for the production of fibers from thermoplastics



Jan. 13, p R HEYMES ETAL PROCESS AND APPARATUS FOR THE PRODUCTION OF FIBERS FROM THERMOPLASTICS Filed May 26, 1947A Fl G. 4. ,2f

24 l 24 INVENToR.

PIERRE Reue Hamasl BY IVAN PLYcHes.

Patented Jan. 13, 1953 PROCESS AND 'APPARATUS FOR THE PRO- V,DUC'ILION OF FIBER-S FROM THERMO- PLASTICS Pierre `Ren Heyrnes and Evan Peyches, Paris, France, assignors to Societe Anonyme des Vlvlanui'actures des Glaces @t Produits Chimiques vde Saint-Gobain, Chauny &Cirey, BariaFrance Application May 26, 1947,"Serial'Nu 750,610 n'France May 31, 1946 .8 Claims.

The present invention; referstto a method .and :apparatus for the manufacture of bers from glassior other thermoplastic materials.

Theimethod according toour invention has for itsobject to submit to the drawing action of a gaseous current produced by the suddenlcss of pressure, :through Aan orifice or orifices, of the products resulting from a previous combustion :.infa 'combustion chamber, the thermoplastic material projected in the form of streamlets'by-centrifugal force, out of a rotating body.

`In that method,.the streamlets of thermoplastic-:material areprojected by centrifugal force in- .to an annular heated zone produced by the products of combustion and are submitted to the drawvinfraction of said Products.

-Accordingto a particular methodfor carrying out our invention the centrifuging body may be located inthe combustion chamber havingits expansion opening in the plane of projection of the streamlets from the centrifuging body.

In another embodiment of our invention the centrifuging body is located outwardly ofthe cornbustion chamber which is constituted by an anm nular chamber surrounding the centrifuging body. Said chamber is provided with an annular eX- `pansionopening, or with a plurality of expansion oricesarranged on a circle, .directing the gaseous yproducts resulting from the combination in sai'dchamber on the streamlets of thermoplas- "tic"materialfprojected.from the periphery cf the centrifuging body. `|The current or currents 'of the products of combustion may be vdirected transversely to` theplane of projection of the streamlets. llheyalso mayhavea component'parallel to thatplane or may be substantially parallel to that plane.

Referring to the accompanying drawings in which corresponding parts are designated by ccrresponding marks of reference,

Figure 1 is a diagrammatic central, vertical section of an apparatus constructed in accordance with this invention and adapted to carry out the process here claimed;

Figure 2 is a similar View of a modified form `ofapparatus FigureS is an inverted View of the centrifuge shown in Figure 2;

Figure 4 is a central vertical section of another 'embodiment of `our invention.

Referringr to Figure l, the centrifuge l is mounted on the upper end of the vertical shaft SWhich may be rotated in any well known manner. VThe-tcp and bottom Walls of the centrifuge converge vto the periphery thereof to form an vejection orifices within combustion chamber t `gener-ally Sym- .feed pipeilu.

equatorial Vzone of .smallwid-th in'fwhich are the The centrifuge is contained metrical with the centrifuge `and thus having its top'and bottom y-.falls approaching eachother vat their perpheries where they are separated by a space to form a-n annular escape nozzle? in the plane of the perforations 2.

A-mixture ofy a combustible gas and air is'simultaneously fed to the combustion chamber above and below the centrifuge by the pipes Sand 5a. The combustible mixture is burnt in the combustionchamber and the gaseous products resulting from the combustion escape through the expansion annular opening l. The shape of the combustion chamber is such that the currents of hot gases, shown by arrows f and g, above and below the centrifuge meet substantially in the planexy containing the lejection perforations 12 to form a resultant current, shown by arrow h, acting substantially in said plane.

Thermoplastic material such as glass, preferably in the form of fragments or balls, is fed to the centrifuge by the chute li located axially thereaboye, entering the centrifuge through an open space in the crown thereof. As pressure eX- ists in the lower edge of the chute provision must be made'to prevent escape of gases from the cornbustion chamber through the chute. Thus two valves Sil and Std in series may be placed in the chute near the top, forming a lock.

inthe operation of this device the thermoplastic material will beejected from the centrifuge by centrifugalforce and after being ejected into the combustion Zone, around the periphery ofthe centrifuge, will be attenuated into libres by the drag exerted thereon by the products escaping through the annular expansion opening 1. The

hot gases of the combustion chamber act also to heat 'the material in the centrifuge. heat it either by contact with the wall of said cen- They can trifuge, as it is the case for the gases introduced below, or by direct contact with the material itself, as'it is'the case'ior the gases introduced at the upper part which penetrate into the centrifuge by the open space in thecrown thereof.

In the arrangement shown in Figure 2 the centrifuge is of the general construction before described in connection with Figure l but is mounted on the lower end of the chute da, being carriedon a bearing-3 formed by a cone on the bottom of the centrifuge and a recessed bearing 8a on the upper end of the combined gas and air In addition, the bottom of the centrifuge has a series of vanes in form of turbine paddles I a thereon moving in the bottom of the chamber below the centrifuge. The gases under pressure resulting from the combustion in this space and escaping out of the annular nozzle 'i cause the centrifuge to rotate at a high speed. The centrifugal adds its action to that of the gaseous current for the attenuation of the streamlets into fibers.

The chute 4a in this case makes tight connection with the top of the centrifuge. The centrifurge is heated by gases burning on the exterior thereof and while pressure exists therein, centrifugal force will be sufficient to cause projection of streamiets of the thermoplastic material.

In both examples shown on Figures 1 and 2 the motion of combustible and comburent gases in the combustion chamber 6 depends upon the shape of the exterior casing of said chamber 6 and upon that of the centrifuging body. The latter constitutes in fact a kind of partition within the combustion chamber by which the movement of the gases and particularly their speed is conditioned. In both these examples where the gases are axially fed, the gaseous currents move in divergent directions from this axis towards the periphery of the chamber. Under these conditions, it is possible to make the speed of the gaseous currents decrease from the center towards the periphery. By giving to these gases near the periphery a speed which is in the neighbourhood of the speed of the flame propagation, it is possible to have for the gases comprised between the center and the periphery of the chamber, a speed which is greater than the speed of the flame propagation. It is consequently possible when desired to localize the combustion in the vicinity of that periphery. To obtain a less localized heating, i. e. extending on a greater peripheral zone of the centrifuging body, it will be suiiicient to give to the speed of the gases slightly lower values than those which have been mentioned hereabove; this may be done practically by modifying the shape of the centrifuge or of the combustion chamber, or by controlling the feeding.

To localize the combustion in certain zones of the chamber it is also possible to use the partition formed by the centrifuge to provide distinct passages for the combustible and for the comburent in order to make them gather and burn in only elected zones of the chamber. Thus in Figure 1 it is possible to feed separately the cornbustible gas and the air by the pipes and 5a, these gases meeting only in the zone where the streamlets of thermoplastic material are formed, at the periphery of the centrifuge.

On the contrary, it is possible, in order to make the centrifuging body and the material it contains benefit of the most important part of the heat produced by the combustion, to introduce the combustible and comburent gases into the centrifuge and to burn them within the centrifuge itself.

In this case the centrifuging body constitutes a part or even the whole of the combustion chamber.

In the construction shown in Figure 4 the centrifuge is tightly carried on the lower end of the tubular member 8, the upper end of which is fast on the inside of a collar 9 having a skirt 9a surrounding, but out of contact with, the tubular member so as to afford space for air insulation between them. The upper part of the collar is surrounded by a pulley groove to receive a belt I2 for rotating the centrifuge, while its lower part receives the inner sections of the runways I 3 of the ball bearings, the opposite and stationary sections I4 being carried by brackets I6 through a tubular casing I5.

The upper end of the casing I5 is closed by the hollow plug I8. This plug has an enlarged head and two skirts I8a and I8b, the outer skirt being of restricted diameter to fit loosely in the interior of the tubular member 8 and so as to form a. restricted annular passage I9 between it and the inner skirt. The combustible fluids are introduced in the plug by one or more pipes 20 and pass down through the annular passage I9 into the centrifuge where they are burnt.

Also carried by the brackets I6 is the stationary annular combustion chamber 6a fed by one or more fuel induction pipes 2l and discharging its products of combustion through an annular slot or nozzle 1a, situated above the equatorial zone in which the apertures in the centrifuge move and through which the material is projected,

The combustion chamber is provided with a double-walled casing enclosing a free space 26 through which an air circulation may be established to protect this casing against the high temperature developed within the chamber. This air may be used as a comburent contributing to obtain a very hot drawing gaseous current.

The bearing I3-I4 may be protected by the water jacket 25.

The heated thermoplastic is fed into the centrifuge through the feed chute 2| formed by the inner skirt of the plug I8 from a suitable feeder 23, as is shown at 22. The products of combustion escape from the centrifuge through holes 24 in its top into a space surrounded by the combustion chamber, and escape outwardly over the top of the centrifuge.

Considering the several forms before described, it will be noted that (a) in each of them the material is projected by centrifugal force and that drag is thereafter exerted on the ejected material by an expanded blast, which, in Figures 1 and 2 is in the plane of projection of the material and at right angles thereto in Figure 4; (b) that in all forms the bres are projected by centrifuging force into a highly heated annular zone, the projection being into the blast throat of the combustion chamber in the forms shown in Figures 1 and 2 and immediately within the blast throat of the latter; (c) that in the form shown in Figure 1 it is possible to have the combustible and air mixed only at the space into which the streamlets of thermoplastic material are projected.

What is claimed is:

1. The hereinbefore described method of attenuating and drawing thermoplastic bers which comprises revolving a body provided with a plurality of openings supporting a source of molten material at sufficient speed to discharge the material by centrifugal force from said openings in fiber form, providing a housing located exteriorly of said body, establishing and maintaining combustible and comburent at high temperature and pressure within said housing, discharging the gaseous products of combustion from said housing to the atmosphere through an annular constricted throat surrounding closely the openings in the centrifuge thereby directing said gaseous products of combustion at high temperature and high velocity into the path of the fibers close to their point of discharge from the openings in the centrifuge and before any substantial loss of heat from the molten fibers to initiate and continue the attenuation and drawing of the fibers close to the discharge point of the centrifuge into the throat of the housing wherein they are entrained and drawn by the gaseous products of combustion passing through and issuing from said throat.

3. The combination of a centrifuge provided with a plurality of openings for the discharge of streamlets of thermoplastic `material therefrom, a housing provided with walls shaped to dene a combustion chamber located exterior to said centrifuge, said combustion chamber being provided with at least one converging wall terminating in an annular throat opening to the atmosphere and surrounding the openings in said centrifuge, said annular throat being positioned to direct a blast of hot expanding gas travelling at high velocity into the path of the streamlets as they issue from the centrifuge whereby said streamlets are attenuated and drawn as they issue from the openings in the centrifuge and before any substantial loss of heat therefrom, and means for maintaining combustible and comburent in said chamber.

4. In apparatus for producing fibers from thermoplastic material, the combination of a centrifuge provided with a plurality of annularly arranged openings for the discharge of streamlets of thermoplastic material therefrom, a housing located exteriorly of the centrifuge and in close proximity thereto provided with walls ldefining a combustion chamber, said housing being provided with an annular discharge aperture opening to the atmosphere closely surrounding the openings in the centrifuge shaped to constrict and thereafter permit expansion of the gaseous products of combustion escaping from said chamber at high temperature and high velocity and to direct said gaseous products of combustion into the path of the streamlets as they issue from the openings in the centrifuge and before any substantial loss of heat therefrom whereby said streamlets are attenuated and drawn as they issue from the openings in the centrifuge, and means for maintaining combustible and comburent in said chamber.

5. In apparatus for producing fibers from thermoplastic material, the combination of a centrifuge provided with a plurality of openings for the discharge of streamlets of thermoplastic material therefrom, a housing exterior of the centrifuge provided with a plurality of walls at least one of which is located above the centrifuge, said walls having a portion converging to form an annular throat opening to the atmosphere surrounding the openings in the centrifuge, said walls being positioned to direct expanding gaseous products of combustion at high temperature and velocity into the path of the streamlets as they issue from the openings of the centrifuge thereby attenuating and drawing the streamlets prior to any substantial cooling thereof from their point of anchorage to the centrifuge and means for maintaining combustible and comburent in said chamber.

6. The apparatus dened in claim 3 wherein the centrifuge with its openings is positioned to discharge the streamlets into the annular throat of the housing and from which they are drawn by the gaseous products of combustion issuing from said throat.

7. The apparatus defined in claim 4 wherein the annular discharge aperture is positioned to direct the gaseous products of combustion transversely of the plane of discharge of the bers from the openings in the centrifuge.

8. In a device for producing bers from thermoplastic material, the combination of a centrifuge having apertures in its equatorial zone, an upright hollow support for the centrifuge having depending skirts, a hollow casing, a hollow annular plug in the top of the casing, having two skirts within the central space of the support, means for introducing combustible gases into the hollow plug, an annular combustion chamber having an annular nozzle above the periphery of the centrifuge, and means for introducing combustible gases into the combustion chamber.

PIERRE RENE' HEYMEs. IVAN PEYCHES.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,289,779 Howard Dec. 31, 1918 2,338,473 Von Pazsiczky Jan. 4, 1944 2,431,205 Slayter Nov. 18, 1947 2,450,363 Slayter et al Sept. 28, 1948 2,497,369 Peyches Feb. 14, 1950 FOREIGN PATENTS Number Country Date 571,807 Germany Feb. 16, 1933 377,806 Italy Jan. 9, 1940 

